Constant pressure mechanism



Dec. 17, 1957 Filed Oct. 21, 1955 v .c. M. PERKINS cousTAN'T PRESSURE MECHANJ'ISM 4- Sheets- Sheet 1 h TIIIIIIIIWTGC;

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INVENTOR. (amass MPemmNs BY r ATTOENEYS Dec. 17, 1957 c. M. PERKINS 2,816,531

CONSTANT PRESSURE MECHANISM Filed 001;. 21, 1955 4 Sheets-Sheet 2 CIULILILIU I flu H II] V Q INVENTOR. Camus: MPEmuNs 772"%0W:g flan/M071 ATTOQNEYS Dec. 17, 1957 C. M. PERKINS ,8

' CONSTANT PRESSURE MECHANISM Filed Oct. 21, 1955 4 Sheets-Sheet 3 INVENTOR. CHARLES M.PERK\NS ATTORNEYS Dec. 17, 1957 c. M. PERKINS CONSTANT PRESSURE MECHANISM 4 Sheets-Sheet 4 Filed Oct. 21, 1955 FIG-Q4- INVENTOR.

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United States Patent CONSTANT PRESSURE MECHANISM Charles M. Perkins, Philadelphia, Pa.

Application October 21, 1955, Serial No. 541,948

2 Claims. (Cl. 123-48) This invention relates to a constant pressure mechanism and has for its primary object to maintain uniform the compression and combustion pressure of a multicylinder internal combustion engine.

Another object is to insure that the compression of the fuel introduced into the cylinders of an internal combustion engine are uniform in each cylinder.

A further object is to facilitate the adjustment of the pressure of the compressed gaseous fuel introduced into the engine cylinders.

The above and other objects may be attained by employing this invention which embodies among its features cylinders carried by the cylinder head of a conventional internal combustion engine and opening into the engine cylinders through said cylinder head, pistons mounted in the cylinders in the cylinder head for movement under the influence of gaseous fuel compressed in the engine cylinders, and means carried by the cylinder head and communicating with the cylinders therein for introducing fluid under pressure into said cylinders on the ends of the pistons therein remote from the engine cylinders.

Other features include means mounted adjacent the engine and operatively connected to the fluid introducing means for regulating the pressure of the fluid introduced into the cylinders in the cylinder head to thereby control the pressure of the compressed gaseous fuel in the engine cylinders.

Still other features include a manifold connected to the cylinders in the head and opening thereinto adjacent the sides of the pistons in the cylinder head remote from the engine cylinders, a pump carried adjacent the engine and operatively connected to the manifold for introducing compressible fluid thereinto and pressure responsive means mounted adjacent the engine and operatively connected to the pump and to the manifold for preserving between selected limits the pressure of the fluid in the manifold.

Still further features include manually actuated means mounted adjacent the engine and operatively connected to the pressure responsive means for governing its response to the pressure of the fluid in the manifold.

In the drawings:

Figure 1 is a diagrammatic view showing this improved constant pressure mechanism connected to an internal combustion engine;

Figure 2 is an enlarged horizontal sectional view through the engine illustrated in Figure 1;

Figure 3 is a vertical sectional view taken substantially on the line 33 of Figure 2;

Figure 4 is a vertical sectional view taken substantially on the line 44 of Figure 3;

Figure 5 is an enlarged sectional view taken substantially on the line 55 of Figure 4;

Figure 6 is a fragmentary perspective view of one form of a flame-proof screen employed in connection with this invention;

Figure 7 is an enlarged fragmentary sectional view taken substantially on the line 7-7 of Figure 6; and

Figure 8 is a fragmentary enlarged sectional view similar to Figure 7, showing a modified form of a flame-proof screen.

Referring to the drawings in detail, an internal combustion engine designated generally 10 is equipped with conventional cylinders 12 in which pistons 14 work in a conventional manner. The ends of the cylinders 12 re mote from the crank shaft of the engine are closed by a cylinder head designated generally 16 which takes the place of the conventional cylinder head and is provided with conventional intake and exhaust valves 18 and 20, respectively, which open into the respective cylinders 12, all in a conventional mnaner. The ports of the valves 18 and 20, respectively, communicate with a conventional intake manifold 22 and an exhaust manifold 24, and each cylinder is equipped with a conventional spark plug 26 by means of which the charge of gaseous fuel admitted thereto through the intake port 18 thereof may be ignited in a conventional manner.

Carried by the cylinder head 10 and opening into each engine cylinder 12 is an auxiliary cylinder 28 in which a piston designated generally 30 is mounted to reciprocate. As illustrated in the drawings, each cylinder 28 communicates with an adjacent engine cylinder 12 so that the inner end 32 of the piston 30 therein defines a movable wall which is adapted to be moved away from the cylinder 12 when the piston 14 moves upwardly on the compression stroke to compress the gaseous fuel introduced thereinto through the intake valve 18. Extending into each cylinder 28 from the movable wall 32 is a stem 34 which carries at its end remote from the movable wall 32 a piston head 36 and opening through the end of each cylinder 28 remote from the engine cylinder 12 with which it is associated is an opening 38 which communicates with a manifold 40 through a nipple 42. It will be understood that the manifold 48 is provided with a nipple 42 for each cylinder 28.

Connected to the manifold 40 is a pipe 44 which is connected to a suitable pump 46 driven by a prime mover 48 which, in the preferred form of the invention, comprises an electric motor. One terminal of the motor 48 is connected through a conductor 50 with ground while the opposite terminal of said motor 48 is connected through a conductor 52 with the low pressure contact 54 of a pressure-controlled switch blade 56. This switch blade is connected through a conductor 58 with one terminal of a source of electrical energy 60, the opposite terminal of which is connected through a conductor 62 to ground. It will thus be seen that when the switch blade 56 engages the low pressure contact 54 of the pressure actuated switch, a flow of electrical energy through the prime mover 48 will be established.

Connected to the manifold 40 through a pipe 64 is a pressure responsive means designated generally 66 which is separated into two separate chambers 68 and 70 by a flexible diaphragm 72. It is to be noted that the pipe 64 opens into the chamber 68 of the pressure responsive means 66 and extending through the wall of the chamber 70 remote from the diaphragm 72 is a plunger 74 which is connected to the diaphragm 72 to be moved under the influence of fluid pressure contained in the chamber 68. The plunger 74 carries intermediate its ends an outwardly extending annular flange 76 and the end of the plunger 74 remote from the diaphragm 72 projects through the instrument panel 78 of the vehicle on which the device is used. The plunger 74 is provided adjacent its end remote from the diaphragm with external screw threads 80 with which is threadedly engaged an adjusting nut 82 which, as illustrated in Figure 1, bears on the instrument panel 78 to move the plunger 74 longitudinally to a selected position. A compression coiled spring 84 encircles the plunger 74 between the flange 76 and the instrument panel 78 and exerts pressure on the stop flange 76 to yieldingly advance the plunger toward the diaphragm 72. It will thus be seen that by turning the nut 82, the tension of the spring 84 may be varied, while the position of the diaphragm 72 will also be altered within the interior of the pressure responsive means 66. Secured to the plunger 74 for longitudinal adjustment thereon are stop collars 86 and 88, respectively, which are adapted to move in a rectilinear path with the plunger 74 and, as illustrated in Figure l, engage the switch blade 56 to move it about its pivot into and out of engagement with the contact 54.

Opening through the wall of the chamber 68 remote from the diaphragm 72 is a port 92 which communicates with atmosphere through a passage 94 and mounted in said wall on the chamber 68 is a valve 96 which is yieldingly held in closing relation with theport 92 by means of a compression coiled spring 98. A solenoid coil 100 is operatively associated with the stem of the valve 96 and one terminal of said coil is connected through a conductor 102 to ground, while the opposite terminal is connected to a conductor 104. The conductor 104 is connected to a contact 108 mounted adjacent the flange 76 and in the path of movement thereof so that when the flange 76 moves under the pressure of the fluid in the chamber 66 and against the effort of the spring 84, a flow of electrical energy will be established through contact 110 and conductor 106 to the conductor 58 to establish a flow of electrical energy through the solenoid coil 100 to open the valve 96. It will thus be seen that when the pressure in the manifold 40 attains a predetermined value, the circuit will be closed through the solenoid coil 100 to unseat the valve 96 and bleed fluid from the chamber 68 and manifold 40 until a lower selected pressure has been attained. Obviously, the pressure maintained in the manifold 40 may be regulated by turning the nut 82.

In order to prevent the flames of the burning fuel from entering the cylinders 28, I provide a suitable flame screen designated generally 114 which, in its preferred form, comprises annular rings 116 and 118 between which extends a disk 120 of metallic wire mesh. As illustrated in the drawings, the annular rings 116 and 118 are clamped betweeen the upper end of the cylinder block of the engine cylinders 12 and the underside of the cylinder head 16 in which position the flame-proof screen 114 will serve to conduct heat generated by the burning fuel away from the interior of the cylinders 28. Louvers 122 are carried by the annular ring 116 and extend downwardly therefrom and partially into the engine cylinders 12, while similar louvers 124 are carried by the ring 118 and extend upwardly into the cylinders 28. In the preferred form of the invention, there are twice as many louvers 122 as there are louvers 124, in order to further interrupt the passage of the flames from the engine cylinders 12 into the head cylinders 28.

In the modified form of the flame-proof screen, illustrated in Figure 8, a single annular ring 126 is provided with transversely extending substantially S-shaped louvers 128, as shown in Figure 8. In some instances, the flameproof screen may comprise spaced grids 130 and 132 between which is disposed a disk 134 of metal mesh screen. It will be understood, of course, that the grids 130 and 132, like the rings previously described, are clamped between the cylinder block of the engine and the cylinder head 16.

In use, it will be evident that through the medium of the pump 46, fluid will be introduced into the compressed fluid manifold 40 so as to exert downward pressure on the pistons 30 and yieldingly hold the Walls 32 thereof against the effort of fuel compressed between the pistons 14 of the engine and the cylinder head 16. By maintaining constant the pressure within the manifold 40, it will be evident that the compression of the gaseous fuel in the various cylinders of the engine will remain constant so that uniform operation of the engine will be experienced. By adjusting the plunger 74 through the turning of the adjusting nut 82, it will be evident that the diaphragm 72 will be governed in such a manner that the pressure within the chamber 68 must be suflicient to overcome the efliort of the spring 84 in order to discontinue the operation of the pump 46 to thus maintain a selected fluid pressure within the manifold 40. Obviously, should the pressure within the manifold 40 exceed a predetermined value, the diaphragm 72 will move the plunger 74 against the effort of the spring 84 and cause the stop flange 76 to engage the contact 108 and move it into engagement with the contact so as to actuate the pressure release valve 96 and allow the fluid in the manifold 40 to escape until such time as it attains a predetermined lower value governed by the pressure on the spring 84.

By employing the constant pressure mechanism, in conjunction with a conventional internal combustion engine, it will be obvious that the pressure of the compressed fuel within the cylinders as well as the combustion pressure will be constant.

While in the foregoing there has been shown and described the preferred embodiment of this invention, it is to be understood that minor changes in the details of construction, combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as claimed.

What is claimed is:

1. Means for preserving uniform the pressure of gaseous fuel compressed in the cylinder of an internal combustion engine comprising a cylinder head having a plurality of upstanding engine cylinders, a reciprocating piston within each of said cylinders, an upstanding auxiliary cylinder superimposed upon each of said cylinders and having the lower end in communication with the top of the adjacent engine cylinder, a piston mounted for up and down movement in each of said auxiliary cylinders, a piston head on the pistons in each of said auxiliary cylinders, there being an opening in the top of each of said auxiliary cylinders, a manifold exteriorly of said cylinder head and connected in communication with the top openings in said auxiliary cylinders, a pump operatively connected to said manifold for introducing compressible fluid thereinto, and pressure responsive means mounted adjacent the cylinder head and operatively connected to said pump and to said manifold for preserving between selected limits the pressure of the fluid in the manifold.

2. Means for preserving uniform the pressure of gaseous fuel compressed in the cylinder of an internal combustion engine comprising a cylinder head having a plurality of upstanding engine cylinders, a reciprocating piston within each of said cylinders, an upstanding auxiliary cylinder superimposed upon each of said cylinders and having the lower end in communication with the top of the adjacent engine cylinder, a piston mounted for up and down movement in each of said auxiliary cylinders, a piston head on the pistons in each of said auxiliary cylinders, there being an opening in the top of each of said auxiliary cylinders, a manifold exteriorly of said cylinder head and connected in communication with the top openings in said auxiliary cylinders, a pump operatively connected to said manifold for introducing compressible fluid thereinto, pressure responsive means mounted adjacent the cylinder head and operatively connected to said pump and to said manifold for preserving between selected limits the pressure of the fluid in the manifold, and manually actuated means mounted adjacent the cylinder head andoperatively connected to the pressure responsive means for governing its response to the pressure of the fluid in the manifold.

References Cited in the file of this patent UNITED STATES PATENTS 1,340,062 Lapham May 11, 1920 (Other references on following page) 5 UNITED STATES PATENTS Folsom May 9, 1922 Cutler Dec. 28, 1926 Bichler June 16, 1931 Hartley Aug. 4, 1931 5 Riffey Mar. 9, 1937 Carnaham Oct. 7, 1952 FOREIGN PATENTS Great Britain July 17, 1908 Great Britain Apr. 23, 1925 France Jan. 8, 1910 Australia Sept. 7, 1926 

